>Muito obrigado, Antonio!
>I confess that I gave a sloppy description of the problem.
>Please ignore the second column (Bore).
>I am looking for the largest difference of depth in two consecutive records. I recieve these data from a measuring device potentially in more than one csv files which I append into that table. Primarily the raw data are not even sorted by depth, so first of all I may have to "translate" these data into an ordered table with an additive column "Position" and then perform your suggestion with the modification of joining the table against itself on D1.position = D2.position +1. (see new attachment)
>Would you agree with that?
>
>Best regards

Sounds about right as long as there are no gaps in Position column values